From The Editor | August 28, 2023

Hyperspectral Imaging's Role In Life Sciences

John Oncea

By John Oncea, Editor

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Hyperspectral imaging is a rapidly developing technique with a multitude of spectral imaging systems having been explored over the last few decades. These systems are being researched for their potential use in the life sciences industry.

A growing number of investments by private companies and government agencies around the world are bringing hyperspectral imaging to the forefront. This technique could be useful in the fields of agriculture, defense, environmental science, industrial settings, forensics, art, energy, and mining.

Researchers are predicting that the hyperspectral imagery market will reach $47.3 billion by 2032, up from its current value of around $16 billion. This growth will occur in the field listed above, as well as in the field of life sciences.

A Look At Life Processes

What are life sciences? North Carolina Biotechnology Center sees it “as science involving cells and their components, products, and processes. Biology, medicine, and agriculture are the most obvious examples of the discipline. However, as science becomes ever more complex, it is more difficult to find clear definitions and boundaries.”

Beyond the study of living organisms and their life processes from biology to zoology, life sciences also can include the development of physical products, such as pharmaceuticals, medical devices, and diagnostics – products designed to treat or help treat patients.

There are other ways to define life sciences, including this take from Leica Biosystems:

Life science studies living organisms and processes. It spans a vast swath of scientific research, from aiding our understanding of microorganisms such as viruses or bacteria to deciphering the physiological processes of the largest land and marine animals on the planet. Life science can be divided into basic science (for example, the discovery of life processes, such as cell division), applied science (for example, new drug candidate testing in clinical phases to manipulate uncontrolled cell division), and translational research (for example, screening a drug compound to treat cancer and using it for medicinal practice).

For our purposes, let’s think of life sciences in its simplest terms, as the study of living organisms and life processes.

Hyperspectral Imaging 101

Hyperspectral imaging (HSI) is a technique that analyzes a wide spectrum of light by combining spectroscopy and imaging to analyze samples in real time. HSI is used in a variety of applications, from medical (disease diagnosis, image-guided surgery, and measuring the optical properties of brain tissue) to food quality analysis (characterizing the chemical constituents of a sample or analyzing samples without contact or contamination) to agriculture (addressing a range of farming issues, such as weeds, diseases, and nutrient deficiency).

The HIS systems market is, according to MarketsandMarkets, “poised to experience a transformative growth trajectory, driven by technological advancements and increasing applications across various sectors. These cutting-edge imaging systems, capable of capturing and analyzing a broad range of wavelengths with unprecedented precision, will revolutionize fields such as agriculture, environmental monitoring, healthcare, and remote sensing.”

As miniaturization and cost-reduction efforts progress, these once-expensive systems are becoming more accessible to various industries and research institutions. This is expected to lead to a surge in demand. Furthermore, by integrating artificial intelligence and machine learning algorithms with hyperspectral data analysis, the capabilities of these systems will significantly improve, allowing for real-time and automated decision-making processes.

So, let’s take a look at what to expect when combining the study of living organisms with a technology expected to experience transformative growth over the next five years.

From A Novel Technique To A Useful Imaging Method

Advanced hyperspectral imaging techniques that were originally designed for applications in remote sensing and astronomy have now found their way into the world of life sciences, according to Biophotonics International. This technology is being utilized for fluorescence microscopy and in vivo imaging, allowing for the simultaneous monitoring of multiple colors and labels, such as fluorophores or quantum dots.

The use of hyperspectral imaging allows for the identification and measurement of various markers within cells and systems, making it a valuable tool in scientific research. Specifically, this technique has shown potential in detecting changes related to cancer in the macromolecules of cells and determining the levels of light-absorbing chromophores. Recent advancements in nonlinear optics have resulted in faster, more adaptable, and more accurate hyperspectral systems that can provide researchers with greater insight and healthcare professionals with more timely and precise diagnostic tools.

“Increasingly, life sciences imaging involves simultaneous monitoring of multicolor labels such as fluorophores or quantum dots,” Biophotonics International writes. “Hyperspectral imaging enabled differentiating and quantitating these labels and provides the basis for studies of not only cellular components but also entire systems.

“Developments in nonlinear optics have introduced faster, more flexible, sensitive, and precise hyperspectral systems, which will provide not only new insight for researchers but also more timely and accurate diagnostic tools for clinical use.”

Clinical Applications

By using hyperspectral imaging techniques, conventionally stained slides viewed through a light microscope can detect changes in staining (metachromasia) caused by cancer-related changes in a cell's macromolecular components. These techniques also can measure light-absorbing chromophores such as hemoglobin and bilirubin. Clinically, this approach can help confirm and quantify the presence of abnormal tissue on pathology slides, resolve "look-alike" questions, and clarify tumor margins in surgical pathology.

Multicolor fluorescence imaging of cells and tissues is one of the most exciting areas for hyperspectral imaging and has been utilized in various research techniques such as:

  • More colors on a single slide
  • Multicolor fluorescence in situ hybridization
  • Imaging of dynamic events within the neuron
  • Ratio imaging
  • Förster resonance energy transfer
  • Lifetime imaging microscopy
  • Spectral karyotyping

By using conventional multichroic interference filters, it is possible to detect up to four fluorescence probes in one cell for multi-parameter studies. However, this can be challenging as the emission spectra of the probes can overlap, making it difficult to distinguish them. To tackle this problem, spectral imaging can be used to differentiate multiple overlapping probes within a single filter passband. The technique is illustrated in the figure, where an AOTF spectral imaging device is used to distinguish three closely spaced green fluorescence dyes in mouse endothelioma.

“Unlike a color camera, spectral imaging provides detailed color information throughout the spectrum. By using techniques such as linear pixel unmixing, quantitative information can be obtained even when there is strong colocalization of the various probes,” writes Biophotonics International. “This technique also has been used to eliminate autofluorescence background from fluorescence samples.”

Up Next

The field of hyperspectral technologies is merging with other life sciences imaging tools, such as bright-field, fluorescence, and confocal microscopes, as well as macroimaging setups. By using spectral imagers in conjunction with other techniques, previously unavailable information can be obtained, increasing the number of imageable probes within a single sample.

For drug development, in vivo techniques that enable real-time visualization of the uptake and effectiveness of therapeutic agents are of particular interest. To observe the event or phenomenon being studied, researchers must choose from various technology options for hyper- and multispectral imaging. In the clinical setting, automated imaging platforms that combine conventional optical microscopes with hyperspectral imaging systems and intelligent software have the potential to revolutionize diagnostic medicine as more diagnostically and therapeutically relevant targets are identified.

Numerous other applications are also being explored, and it is likely that interdisciplinary efforts involving physicists, engineers, life scientists, and physicians will be necessary for their successful development and implementation.